[HTCondor-users] File transfers and symlinks along the path

[Steffen Grunewald <steffen.grunewald@xxxxxxxxxx>]

Good afternoon,

we've been running our HTC clusters for many years now, always automounting
the "home" tree (served by a single NFS server) as a whole into /.auto and
symlinking /home -> /.auto/home (as automounting individual homes per-user
looked like wasted cycles to us).
All the time we didn't face any issues with that approach - in particular
because file transfer wasn't necessary at all, with filesystems shared
across the whole pool.


Now the situation has changed, and while we suspect that our job generator
is part of the problem and mixing up the results of `pwd` and `pwd -P` (or
the equivalent in Python code), we also see HTCondor contributing to it:

We now frequently find transfer file paths that start with a bunch of "../"
(to traverse back to the / directory) and then append "home/${user}/foo/bar/baz"
to that when the relative path would just be "baz".
"initialdir" (in job classAd: Iwd) is set to "/.auto/home/${user}/foo/bar".
This doesn't cause any problems anywhere else, it's just the shadow that
finds out about the symlink right in the middle of the path and refuses to
transfer the file - causing the job to be held.


My questions now are:
Since this is intended behaviour, may I learn about the rationale behind it?
Is there a means to work around it in HTCondor, or do we have to abandon
the old mount strategy?


Thanks,
 Steffen

-- 
Steffen Grunewald, Cluster Administrator
Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
Am Mühlenberg 1 * D-14476 Potsdam-Golm * Germany
~~~
Fon: +49-331-567 7274
Mail: steffen.grunewald(at)aei.mpg.de
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